Evaluation of Drug Interactions of Saxagliptin With Sildenafil in Healthy Volunteers

Patients with diabetes are three times more likely to develop erectile dysfunction (ED), and longer duration of diabetes is strongly associated with ED. The possibility of pharmacokinetic interactions may occur as the two drugs are metabolized by hepatic CYP3A4 and their co administration may affect their plasma concentrations. the aim of work is to investigate the effect of sildenafil a CYP3A4 substrate and inhibitor on the pharmacokinetics and safety of Saxagliptin, a CYP3A4 substrate Subjects and Methods: Eighteen healthy volunteers will be recruited in Sequential, single center study to determine pharmacokinetic parameters of Saxagliptin, and sildenafil,(AUC0→∞), (AUC0→t); Cmax; tmax; t½, k; ka) will be measured using validated LC-MS/MS method. Therapeutic doses will be given to volunteers as follows: Sildenafil 50 mg single dose on day 1, then washout period from day 2 till day 8. Saxagliptin 5 mg once/day will be given from day 9 till day 12, then on day 13 the two drugs will be co-administered. Blood samples (5ml) for pharmacokinetic analysis will be collected on days 1 and 13 for Sildenafil as well as on days 12 and 13 for Saxagliptin.